Sieve



E. HEYMAN July 14, '1931.

SIEVE Filed June 25, 1928 V2` Sheets--Shee'cl 1 IIR-H July 14, 1931. E. HEYMAN 1,814,552

SIEVE Y Filed June 23,2 1928 2 Sheets-Sheet 2 R Jnvenof l E NST HEYMAN Patented July 14, 1931 Unire ERNST HEYMAN, F FRANKFORT-ON-THE-MAIN, GER-MANY SIEVE Applicationkled. June 23, 1928, Serial No. 287,806, and in Germany July 2, 1927.

This invention relates to sieves and more particularly to devices of this kind which serve for sifting, separating, sorting or classifying material of any kind. For this purpose heretofore sieves have been used which had been shaken or otherwise properly moved in order to cause the liner particles of the material to fall through. the meshes of the sieve. In this case, however, it had been impossible to prevent the meshes of the sieve from clogging-up and special brushes or similar auxiliary devices had to be employed in order to remove the particles of the material which had collected within the meshes of the sieve.

My invention provides a novel sieve, separating, sorting, classifyingor sifting device which is of simple and efficient construction and positively avoids the above-mentioned drawbacks inherent to sieves of ordinary construction. More particularly, the device according to my invention is so constructed that it will positively prevent any particles of material from remaining within the meshes of the sieveand that the effect of sifting will be accomplished by the aid o f a special auxiliary device which serves for properly distorting the meshes of the sieve. According to my invention the sieve which 13.0 serves for the reception of the material to be treated is provided with a distorting device having prong-like members that properly engage with the meshes of the sieve, as well as a driving mechanism for imparting '35 to said sieve or said distorting device a 'properr motion whereby the distorting members proper will periodically engage and distort the meshes of the sieve, in order to cause the finer particles of the material toV 4.0 fall through said meshes. In some cases, especially 1f sieves. are employed having a structure whichmayeasily be damaged, itV

may be of advantage to construct the distorting device in such away that it vwill not immediately engage the meshes of the sieve. For this purpose a modified form of sieve according to my invention may Vbe preferable, this modified sieve comprising distort- .ing prongs which are connected with the 59 meshes so as to project out of the allie surface of the sieve. The distorting device further includes actuatmg members which serve for operatmg said prongs so as to 1m- 'part a periodical distortion to the meshes of the sieve. The vdistorting device itself may in this case consist of an auxiliary sieve of chain-like structure, a number of upwardly projecting rods or bars being connected with said auxiliary sieve. This distorting device is mechanically actuated by the aid of a driving mechanism in such a manner that said device will make an oscillating or eccentrical motion, the said rods or bars coming thus periodically into and out of engagement with the distorting prongs `that are rigidly fixed Vupon the meshes vof the sieve. Instead of the aforementioned distorting device also other distorting means may be employed such as, for instance, a metal-sheet having flaps of prong-like conformation which are cut and bent out of said metal-sheet. Furthermore, said Vdistorting means' may consist of a circularly moving perforated plate, the pronglike members which are connected with the meshes of the sieve co-operating with the perforations of saidl plate.

A further modified construction of the lsieve according to my invention comprises a distorting mechanism by means of which the material may not onlyk be sifted, separated or sorted but also moved forward upon the active` sifting surface of the sieve. This modiied construction comprises a fixed sieve equipped with-distorting prongs rigidly connected with the meshes of the sieve Aand further distorting members co-operating with said prongs. In addition to this there is provided a driving' mechanism for actuating the distorting device in Such a manner thatits several members will move periodically past the prong-like extensions onthe sieve and in a direction opposite to the desired direction of motion of the material. By this the several meshes of the sieve will always be distorted in the same direction so that the material on the one hand will kbe sifted, sorted or separated andon the other hand moved forward upon the surface of theseva ,Simultaneously with this forward motion of the material there will be effected a sifting as well as a sorting of the material according to its specific gravity. This mode of operation will of course essentially accelerate the process of treating the material and dispense with any special devices or contrivances which according to the present practice are necessary for this purpose.

A preferred modified construction of the aforementioned kind which may be used for simultaneously sifting and feeding the material to be treated comprises a distorting device consisting of several rollers which are arranged in spaced relation toV each other below or above the surface of the sieve and commonly rotated in the same direction, said rollers being provided on their circumference with prongs or similar extensions co-operating with the distorting prongs on the fixed sieve. T he driving mechanism may of course also be constructed in different ways, for instance an endless conveying belt carried by a pair of rollers may be used and the actuating members co-operating with the distorting prongs of the distorting device may be fixed on said conveying belt.

A still further modified form of the device according to my invention comprises a sieve which is subdivided into a plurality of steps of horizontal or inclined arrangement. According to my invention, however, also a sieve of an elevator-like construction may be used in which the several steps of the sieve are arranged to present a greatly inclined sifting surface,the actuating members for the distorting prongs in this case Ybeing intermittently moved in order' to impart to the material an almost vertical lifting motion due to the effect of acceleration exerted by the distorting prongs on the sieve. The several steps of the sieve furthermore may be of sieve-like structure so that a thorough sifting will take place simultaneously with the upward motion of the material.l The special advantage of this modified construction by means of which the material may be simultaneously sifted and moved forward at a fixed position of the sieves consist therein that the mode of operation will be essentially simplified and the cost of construction of the entireplant considerably' .reduced as comparedl with heretofore constructed plants of the present kind. p Y

Av further especially advantageous modified construction maybe provided according to my invention byemploying a sieve which is made in the form of an encless conveying belt. On the one hand this con'- veying belt is equipped with a lifting device, such as transverse ledges, and on the other hand with distorting prongs fixed to the meshes of the sieve. The endless belt is; furthermore so mounted upon rollers that there will be produced at least one perpendicular or inclined sifting surface which projects into a container and in addition to this at least one further horizontal sifting surface. On the said perpendicular or inclined sifting surface the material will be lifted out of said container, while on the horizontal sifting surface the material is sifted by action of the distorting prongs which pass the xed actuating members cooperating therewith.

In the accompanying drawings I have shown a few constructions of my improved sieve and the distorting device associated therewith, Fig. 1 being a section through one form of my device, Fig. 2 an enlarged perspective view showing details of the distorting device, Figs. 8 and l are partial sections through modified forms of the device, showing forms of the distorting prongs which are rigidly connected with the meshes of the sieve, Fig. 5 is a section through a modified form of sieve serving simultaneously for sifting and conveying of the material, Figs. 6 and 7 show different constructions of distorting devices for stepped sieves, and Fig. 8 shows a further modificationv of the sieve comprising a rotary conveying and sifting device constructed Vaccording to the principles of my invention.

Referring more particularly to the drawings, 1 designates a sieve composed of meshes, the material to be sift-ed,` sorted or separated being supplied to said sieve by the aid of a hopper or similar device. The sieve 1 is mounted within a frame 2 and below said sieve there is provided the distortingV device in the form of a distorting' sieve l composed of meshes 5. Upwardly projecting prongs 6 are rigidly connected to the several meshes 5 of the distorting sieve 4, said sieve being suspended intermediate two fixed supporting ledges 11 by means of four springs 10. Motion is imparted to the sieve et by a driving mechanism consisting of an electric motor 20, a sprocket-wheel 21 mounted on the shaft of said motor anda chain 22. The latter serves for driving a similar sprocket-wheel 23 mounted on a shaft 19. Fixed to the shaft 19 which-is supported by bearings 1S are cam-'discs 17 having cams 17 which serve to operate the front members 6 of the Ameshes of the working sieve when being distorted. The cams 17 are so arranged that the entire distorting sieve will slowly move towards the right and again be caused tov quickly move backward by action Vof said springs after being disengaged from said cams. The distorting prongs will engage with the meshes of the sieve either only during backward motion or also only' during forward motion of the sieve, said prongs causing a distortion of the meshes of the sieve in order to bring about the desired sifting effect.

It will also be possible without further complicating the devices to impart a rotary motion to the working-sieve, for instance by means of an eccentric, in such a manner that 'the' distorting prongs in the uppermost position of the eccentric will engage with the sieve to bring about a distortion of its meshes.

In the construction according to Figs. 3 and 4 the sieves 7 are mounted with a frame 2. These sieves 7, however, are provided with downwardly projecting members 3 which are rigidly connected to the several meshes, said members 3 being shown in Fig. 4 of somewhat greater length than in Fig. 3. The distorting device consists of a metalplate 9 from which prong-shaped fiaps 12 are cut and bent out to project towards above. The metal-plate 9 is connected with the cranks 13. `Upon the shaft of the righthand driving crank there is mounted a sprocket-wheel 23 which engages with the chain 22 and lco-,operates with the small sprocket-wheel 21 vprovided on the shaft of the motor 20. The mode of operation in this case is essentially the same as with the aforementioned modiication. The members 12move past the downwardly projecting prongs 8 during each rotation of the crank thus imparting the proper distortion lto the meshes of the sieve, the original conformation of the meshes being 'immediately restored by action of the natural tension of the sieve, whenever f the members 12 have passed the meshes.

According to Fig. 4 the prongs 8 engage with the perforations 15 of a perforated plate 14, which is driven by means of a shaft 16 connected to said plate at a point at some distance from its center, said shaft 16 being mounted in bearings 16. If the plate 14 is rotated, the prongs 8 will be bound to remain upon the surface of the plate, while during passage of a perforation said prongs will enter thereinto. By this also an accelerated motion will be impartedto the sifting prongs therewith producing the desired distortion of the several meshes of the sieve. As shown in Fig. 5, the working sieve 1 is iiXedly mounted within the frame 2 and the meshes of the sieve are again provided with downwardly projectingprongs 8 rigidly connected to said meshes. The material to be sifted is supplied to the sieve by means of a hopper. Below the working sieve 1 there are provided rollers 26 side by side certain distances from each other, said rollers carrying on their circumferences pronglike extensions 27. A sprocket-wheell 28 is mounted exteriorly on each of said rollers,

the several sprocket-wheels being connected with each other by means of the chain 24 in such a manner that the direction of rotation of all sprocket-wheels will be the same.

The first roller is driven by a special drivthe motor 20. lIhre several rollers are rotated 1n the direction indicated by arrows 'in Fig. 5. rllhe` prongs 27 will periodically s come in engagement with the prongs of the working sieve and the several meshes of said sieve will thus be periodically distorted. The distortion ofthe meshes takes place in such a manner that after passage of each of the prongs 27 said meshes will Vsuddenly be pushed backward by action of the natural tension of the structure of the sieve, thus imparting a feeding motion to the material on thefsieve as indicated by the arrow shown in Fig. 1 above the sieve. The material will now be fed forward on the surface of the sieve and at the same time sorted, separated or the like, whereupon it will pass into the container/29.

`In Fig. 6 the sieve 31 is subdivided into several stepped sieve-surfaces. In this construction there are also provided downwardly projecting prongs 33 at those places 32 of the sieve which form the afore-mentioned stepped surfaces. The prongs 33 will come in engagement with further prongs which are provided on an endless belt 34 carried by the drums 36 and co-operate with said formed prongs.` The endless belt 34 is driven by a motor 20, two-sprocket-wheels 21 and 23 andthe chain 22 serving for transmitting the motion as shown in the drawing. During motion of the prongs 35 past the prongs 33 an accelerating motion will be imparted to the meshes of the sieve Vand accordingly the material resting thereon will be moved forward and sifted. According to Fig. 7 the material is conveyedby means of a supply-hopper 30 to the inclinedsieve 31. In this construction the sieve is composed of Vvaplurality of stepped sieve-surfaces 40.1 The Vheight'ofvthe several steps inf the Ypresent case is somewhat smaller-1in"accordance with the greater inclination'of the'sieve. "The meshes vof vthe sieveare provided with prong-shapedxextensions 33 which areV` actuated by rollers 38 rotating at even speed'l in the same sense lof rotation.A On the peripheries of the rollers there are Vprovided prongs 37 which are driven inthe manner above described 1n connection with Fig. 5 by the aid of chainsy and sprocket-wheels by a motor `20. The material will move in the direction indicated by the arrow in Fig. 7 by being thrown upwardly ,from one step of the sieve to another and finally discharge into 'Y the container 29.

:Each ofv these deflecting rollers, carriesy Qn its outside a sprocket-wheel which is engaged by the driving chain. The endless belt is driven by a special sprocket-wheel 23, a chain 22 and a further small sprocket-wheel mounted on the shaft of the motor 20. Lifting devices in the ferm of transversely positioned ledges 44 are provided on the sieve or endless belt 48 which ledges are only fastened on the edges of said sieve or belt in order to enhance the flexibility of the latter. Besides7 the meshes of the sieve are again equipped with prong-shaped extensions rigidly connected to the several meshes. The distorting device proper forming part of the construction according to Fig. 8 is ixedly mounted within a frame 45 and consists of a plate 47 having a plurality of downwardly projecting prongs 47 which are positioned Within the range of action of the members 45. The right-hand end of the sieve or endless belt projects into the main container 48 and the ledges 44 serve for lifting the material out of said container 48. On the upper horizontal main portion of the surface of the sieve the distorting prongs 45 will come in engagement with the members 47 co-operating with said prongs so that the meshes of the sieve will be distorted and the material sifted as above described. Finer particles of the material will be discharged from the device by way of-an incline 49 projecting thereinto to a further container (not shown), while the coarser particles which do not fall through the sieve will pass at the rear end of the left-hand upper deflecting roller into a container SO.

This embodiment of my invention may, of course, be constructed with four or more defleeting points in the endless conveyor or sieve whereby a plurality of sieve faces are provided which, for instance, may form a parallellogram. The endless sieve may thus be conducted in any desired course and may be adapted to transport the material along any desired path. The returning section of the sieve `may be utilized for sifting the material a second` time.

The last described embodiment ensures a very uniform distribution of the material over the sieve and is particularly adapted for moist material which is likely to get stuck in the meshes. Owing to the repeated turning of the material attained -in this band is particularly adapted for drying plants. In this case, means are provided which conduct a gaseous heated drying medium, such as hot air, through the falling material and which, owing to the easy accessibility of the sieve, may be arranged in a very efficient position.

I desire to be understood that my invention is not confined to the exact constructions described herein. My invention, generally speaking, may be employed with all kinds of sieves or similar devices which serve for sifting material, for instance ores, coal-dust, cement and the like, of organic as well as of inorganic nature, it being further immaterial whether the material is subjected to a dry or wet process of treatment.

I claim:

A device for sifting, sorting or separating and conveying material, comprising a working sieve having a stationary and immovable frame and composed of meshes, distorting prongs rigidly connected to said meshes, at spaced points from the surface of said sieve, a plurality of spaced rollers mounted adjacent to said sieve, driving means for commonly imparting uni-directional motion to said rollers, and prong-like extensions on the periphery of said rollers, said prong-like extensions being cooperative with said distorting prongs.

In testimony whereof I aixed my signature.

ERNST HEYMAN. 

